The goal of this pilot study is to explore a combination of two interventions: (1) a behavioral alcohol-reduction intervention using motivational interviewing, and (2) a blinded probiotic microbiome or placebo intervention. The study examines whether these interventions improve cognitive and neurophysiological function, including brain metabolism, in older adults who are high-risk alcohol drinkers.

Inclusion Criteria:

• Between 65 and 84 years of age
• English speaking
• Able to provide valid informed consent, understand requirement and risk/benefits of the study and comply with study protocol
• Heavy drinker defined as >14 alcoholic drinks/week for men and >7 drinks/week for women
• Interested in reducing their alcohol consumption

Exclusion Criteria:

• BMI ≥ 35
• Fasting Glucose > 125 mg/dL
• Current or previously diagnosed with Type 1 or 2 Diabetes
• Requires the use of insulin and/or other glucose lowering agents
• Unable to fast for 12 hours
• Past serious alcohol withdrawal symptoms
• MRI Contraindications (e.g., certain devices and implants, claustrophobic)
• Diagnosed with a neurodegenerative disease (e.g., Alzheimer's Disease)
• Diagnosed with a psychotic disorder
• Current substance dependence diagnosis (except for mild or moderate alcohol)
• Consumption of over 300 drinks in the past 30 days
• Current probiotic use or recent probiotic use within the past 30 days
• Current antibiotic use or recent antibiotic use within the past 30 days
• In active cancer treatment and/or have advanced cancer
• Taking daily steroids and/or immunosuppressants
• Lifetime organ or bone marrow transplant; primary immunodeficiency (e.g., DiGeorge syndrome or Wiskott-Aldrich syndrome) or transplant recipient or prescribed immunosuppressant medications
• PI's discretion